carray: add offset to carray-buf.

* ffi.c (struct carray): New member, offs.
(make_carray): Initiialize offs member from new argument.
(copy_carray, carray_blank, carry_ptr, carray_sub,
carray_pun, carray_unum, carray_num): Pass zero offset to
(carray_buf): New optional parameter off_in.
(carray_buf_sync): Handle offset.
(ffi_init): Update registration of carray-buf.

* ffi.h (make_carray, carray_buf): Declaration updated.

* txr.1: Documented.

1 files changed, 2 insertions, 2 deletions

diff --git a/ffi.h b/ffi.h
index 880ee2d3..33ee549a 100644
--- a/ffi.h
+++ b/ffi.h
@@ -90,7 +90,7 @@ val ffi_put(val obj, val type);
 val ffi_in(val srcbuf, val obj, val type, val copy_p);
 val ffi_get(val srcbuf, val type);
 val ffi_out(val dstbuf, val obj, val type, val copy_p);
-val make_carray(val type, mem_t *data, cnum nelem, val ref);
+val make_carray(val type, mem_t *data, cnum nelem, val ref, cnum offs);
 val carrayp(val obj);
 val carray_set_length(val carray, val nelem);
 val carray_dup(val carray);
@@ -103,7 +103,7 @@ mem_t *carray_ptr(val carray, val type, val self);
 val carray_vec(val vec, val type, val null_term_p);
 val carray_list(val list, val type, val null_term_p);
 val carray_blank(val nelem, val type);
-val carray_buf(val buf, val type);
+val carray_buf(val buf, val type, val offs);
 val carray_buf_sync(val carray);
 val carray_cptr(val cptr, val type, val len);
 val vec_carray(val carray, val null_term_p);